Unigrit Foam Finishing Disc questions

[termigator69]

I am planning on repainting my car and then wetsanding it with the new Unigrit Foam Finishing Discs. I do have a few questions before taking the plunge:

1. Will the Foam Finishing discs fit the 6" LC backing plate I have on my PC?

2. Do I need the 6" Micro Hook/Loop Foam Interface Pad?

3. What's the difference between the Unigrit Sanding Discs and the Unigrit Foam Finishing Discs? (Answer might seem obvious, but since I have to order the stuff, I just want to make sure.)

4. Any other recommendations on what I might need for wetsanding my car?

Thanks.

[Mike Pennington]

Re: Unigrit Foam Finishing Disc questions

I am planning on repainting my car and then wetsanding it with the new Unigrit Foam Finishing Discs. I do have a few questions before taking the plunge:

- Can't wait to see the results...

1. Will the Foam Finishing discs fit the 6" LC backing plate I have on my PC?

They should, but just make sure the sanding / backing plate does not extend past the finishing disc. Keep in mind though, the "hook / loop" may not match, so that could prematurely wear out the discs or cause them to not attach properly. Best practice / results would be achieved by our matching backing plate and discs.

2. Do I need the 6" Micro Hook/Loop Foam Interface Pad?

Yes, when using our Sanding Discs, the interface pad is recommended but optional, but when using our Finishing Discs, it is a must !!

3. What's the difference between the Unigrit Sanding Discs and the Unigrit Foam Finishing Discs? (Answer might seem obvious, but since I have to order the stuff, I just want to make sure.)

Our Sanding Discs are designed to "level" texture, as in orange peel, and quickly remove serious defects. The Finishing Discs are designed to refine the sanding marks created by a sanding dics and/or remove light to moderate defects on it's own. Depending on how the paint looks out of the booth and your expectations, you may need one or both types of discs....

4. Any other recommendations on what I might need for wetsanding my car?

How many cars have you painted and/or sanded in the past ?

[termigator69]

Re: Unigrit Foam Finishing Disc questions

Thanks for the info. This is my first venture into painting an entire car. I've done a few spot repairs with a spray painting (spray can) and wetsanding. Results have been mixed.

I already have the 25 pack Meguiar's Unigrit sandpapers in 1500, 2000 & 2500 grit. I also have the sanding pad along with a 1500 & 2000 grit sanding block. I plan on using the pad in the tight areas, but I want to be able to machine wetsand the larger surfaces for expediency sake.

[DetailFreak517]

Re: Unigrit Foam Finishing Disc questions

Mike, I have a couple more questions for you about these new discs:

1) I'm sure these can be used with either electric or air DAs, but are there any recommendations about what specifications the tool used should have to achieve optimum results? For example the speed in OPMs, DA stroke length, etc.?

2) How many discs are typically needed to complete an average sized car? Just wondering if I'll need to buy full boxes of 15 or if I can get away with buying fewer discs from a supplier like ADS that sells them in lower quantities.

Thanks!

[termigator69]

Re: Unigrit Foam Finishing Disc questions

I know Mike Phillips said he used 6 3000 grit discs to sand a car for DetailFest. I would guess I'm going to need just a few more.

[DetailFreak517]

Re: Unigrit Foam Finishing Disc questions

I know Mike Phillips said he used 6 3000 grit discs to sand a car for DetailFest. I would guess I'm going to need just a few more.

Right.... I think he told me 5 total on that El Camino he did. I just wondered if Mr. Pennington would have a different answer. Also curious if tool selection makes any sizable difference in performance of the abrasive product.

[Michael Stoops]

Re: Unigrit Foam Finishing Disc questions

There are a few guidelines to follow when using these discs:

• Remember that you are damp sanding with these, not wet sanding. Don't presoak the discs and don't flood the surface with water. All you need is a spritz or two of plain water on the surface and the disc. Too much water will cause a hydroplaning situation and you'll lose cut.
• Keep in mind, too, that your initial pass with a new disc may not result in the level of cut you anticipate. There is a protective coating on these disc (the induction layer) that will need to be worked through first before the disc starts cutting. It's pretty quick to happen, but at first glance it can throw you if you aren't aware of it.
• If you're going to use an electric D/A please keep in mind that none of them on the market are rated for wet use. Granted, you're not using a lot of water here, but water and electricity don't mix so be cautious. You can do it, and you should experiment with speed settings around 4 to 5. Too slow and you'll dig a bit deeper, too fast and you'll start to hydroplane again and lose cut.
• Pressure should be no more than the weight of the tool.
• Regular cleaning of the disc is important as well. A quick spin on the tool against an Ultimate Wipe microfiber towel with very light pressure will clean the disc out very effectively. Do this whether using air tools or electric, of course.

Mike Phillips may have been overly cautious when using 6 of the 3000 grit discs as Jason Rose tells us you can get away with as few as 2 on a full sized car. Now that's specific to the 3000 grit discs - the lower the grit the faster they'll wear out (as a general rule).

These discs are designed to be used with a 5/16" stroke tool, which fits well with the G110v2 and pneumatic orbital sanders of similar stroke.

[DetailFreak517]

Re: Unigrit Foam Finishing Disc questions

Awesome! Thanks for the info, Michael.

[termigator69]

Re: Unigrit Foam Finishing Disc questions

That's a whole lot of good info. Thanks Mike. I'm still in the process of gathering materials for the project. I would like to start and finish during the month of May. If it doesn't get done then, I'll have to push things back to September. I have three kids (Ages 5,7 & 9) and I just can't see myself getting anything done during their summer vacation.


Mike:
On a somewhat different subject matter, what are your thoughts on the DupliColor Paint Shop System? I checked out their website and their system seems easy enough, but as I researched it more on different paint forums, they don't seem to really like it that much for the single reason that it's lacquer based (which they consider yesterday's technology) instead of acrylic or urethane. Any input would be extremely helpful. Thanks.

[Michael Stoops]

Re: Unigrit Foam Finishing Disc questions

RE: Duplicolor Paint Shop System - I'm afraid I'll have to defer to the painters here on MOL as that's not really my area of expertise. Perhaps SHYNEMAN123 can weigh in here.

[DetailFreak517]

Re: Unigrit Foam Finishing Disc questions

On a somewhat different subject matter, what are your thoughts on the DupliColor Paint Shop System? I checked out their website and their system seems easy enough, but as I researched it more on different paint forums, they don't seem to really like it that much for the single reason that it's lacquer based (which they consider yesterday's technology) instead of acrylic or urethane. Any input would be extremely helpful. Thanks.

I don't see a problem with Lacquer based paints in some applications. It really depends what you're going to use the vehicle for whether or not it's the best choice.

Have you checked out Eastwood's paint system, or the new paint system from Summit? I've heard very good things about both, and they offer both catalyzed and non-catalyzed systems for you to choose from depending on what you want or need.

[Mike Phillips]

Re: Unigrit Foam Finishing Disc questions

I know Mike Phillips said he used 6 3000 grit discs to sand a car for DetailFest. I would guess I'm going to need just a few more.

Just to clarify...

I used 4 and started using a 5th disc. This was the first full sizes car I completely sanded down and I'm talking about pretty much all the exterior paint. There's a learning curve to using these discs correctly as too little water and you'll clog the disc and wear it out prematurely, and too much water and the disc will simply hydroplane instead of cut.

Now follow me on this, if the disc is hydroplaning, this can fool you into thinking it's not cutting...

So there's a bit of a learning curve to using the discs efficiently.

I did my best to try to sand as long as I could with a single disc before switching to a new one and it could be I switched prematurely, but I did take a moment to check on un-sanded paint by sanding for a few strokes and then gauging the results and if it looked like cutting efficiency was falling off then I switched discs.

I've been pretty busy with a lot of other projects but I do have MOST of a write-up on the process I used finished in MS Word and lots of pictures to go with it.

I did measure how much water I used by filling a 32 ounce spray bottle with water and then after I was completely finished sanding I took a picture of the bottle and it was half full, so that means I used about 16 ounces of water over the entire 1969 El Camino.

If you can't bring the car up to you... bring yourself down to the car...




Every square inch was machine sanded, even into tight corners with curved panels. I never used my hand to sand one inch of the El Camino. The backing plate is designed to flex and curve. I did turn the speed down for tight areas, remember there's a huge difference between a DA Polisher keeping a foam pad rotating and a thin sanding disc.




I could have started out with the #1500 grit paper but I didn't know anything about the paint job except it was a custom paint job and had already been sanded and compound once. The paint was completely swirled out and had lots of RIDS and ARC Scratches everywhere.



When I come across a project like this I like to play it safe and use the least aggressive product to get the job done and the #3000 Unigrit Disc cuts very good.

Note I didn't just "scuff" the paint... I sanded it down...

The white stuff for anyone reading this wondering what that is, that is clear coat paint that has been sanded off and was in the water film on the panel. After the water evaporates off it leaves the clear coat residue which after being abraded is whitish.


Machine Damp Sanded




So follow Meguiar's recommendations for using these new Unigrit Sanding Discs, focus on the task at hand and you can't help but get show car results...


After a "Complete" Machine Polishing Process

[Mary S]

Re: Unigrit Foam Finishing Disc questions

Just curious, I note that Meguiars only sells these in 1500 and 3000 grit. Will these always be enough? Would you sometimes need 2000 or 2500?

[Michael Stoops]

Re: Unigrit Foam Finishing Disc questions

Just curious, I note that Meguiars only sells these in 1500 and 3000 grit. Will these always be enough? Would you sometimes need 2000 or 2500?

The vast majority of the time going from a 1500 to 3000 grit finishing paper is all you really need - there shouldn't be a need for anything in between these two, and a 3000 grit finishing mark will just be easier to buff out than anything more coarse.

It should also be noted that we have the 1500 grit sanding disc in 6" diameter which will cut faster and level texture more readily than a 1500 grit finishing disc.

Of course in the 3" size we have sanding discs down to 320 grit for headlight restoration and paint spot repair.

[termigator69]

Re: Unigrit Foam Finishing Disc questions

I don't see a problem with Lacquer based paints in some applications. It really depends what you're going to use the vehicle for whether or not it's the best choice.

Have you checked out Eastwood's paint system, or the new paint system from Summit? I've heard very good things about both, and they offer both catalyzed and non-catalyzed systems for you to choose from depending on what you want or need.

I liked the Duplicolor system because it comes readily mixed. The car is not exactly going to be my DD, but it will be sitting outside 24/7. From what I've heard so far, lacquer is best used for garage queens.

I have the Eastwood catalog and I'm sort of leaning towards their urethane paints. I'm just a little annoyed that they sell the paint in gallons and the activator in quarts, but then the paint requires a 3:1 mix ratio. What the #%$& am I supposed to do with the other quart of paint without any activator?!

I was not aware that Summit sold paints too. I'll have to look into that. You're talking Summit Racing, right?